Improvement in steam-engines



s.v. FRANK.

Steam-Engine- N0,l69,249. Paxentedocnzamm.

UNITED STATES yPATENT OFFICE SAMUEL B. FRANK, OF MARSHALL, MISSOURI.

IMPROVEMENT IN STEAM-ENGINES.

Specification forming part of Letters Patent No. 169,249, dated October 26, i875 application tiled October 6, 1875.

To all whom it may concern:

Be it known that I, SAMUEL B. FRANK, of Marshall, in the county of Saline and State of Missouri, have invented certain new and useful Improvements in Steam-Engines; and I do hereby declare that the following is a full, clear, and eXact description thereof, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

The nature of my invention consists in the construction and arrangement of a steam-engine worked by four pistons, with two connections, as will be hereinafter more fully set forth.

In the annexed drawing, Figure l is a plan View of my improved steam-engine. Fig. 2 is a longitudinal section ot' the same. Fig. 8 is a transverse section through the line y y, Fig.

2. Fig. 4 is a plan View ofthe steam-cylinde in reduced dimensions. f A represents the ordinary steam-chest, provided with two ports, c and b, which are divided into tive channels, c1 a2 a3 and bl' b2, so arranged that the steam will pass from the chest bythe port a along the three channels al, a?, and a3, into the cylinder, said three channels or inductions opening into the cylinder, one at each extremity and one midway thereof. The steam will pass from the chest by the port b along the two channels bl b2 into the cylinder at points one-fourth the distance, respectively, from the ends of the cylinder. B represents the cylinder, in which are arranged four piston-heads, C' C' and D' D', each of which traverses or plays one-fourth of the length of the cylinder. C C are the pistonrods for the piston-heads O' C', and are made hollow, as shown. D D are the piston-rodsfor the piston-heads D' D', and are made solid.` The piston-rods O (l and D D are connected to cross-heads E E and Gr G, respectively, and the solid rods D D pass through the hollow rods O G. The outside cross-head G at each end connects with the inside crosshead E at the opposite end by means of rods d d, as shown in Fig.'1. The two cross-heads E and Gr at the front end of the cylinder are by ordinary strap-joints and connections E H' connected with wrists I and I', respectively, said wrists being so set as to be always at opposite points. The steam entering the cylinder lthrough thechannels b1 b2 forces the two piston-heads C' AO' to the ends of the cylinder, and the other two piston-heads to the middle of the cylinder, and then when the steam enters through the threel channels al, a?, and a3, it forces the piston-heads O' D' on one side of the center toward each other to a point one-fourth ,of the distance from one end of the cylinder, and the other two pistonheads in similar manner to a like point from 'the other end of they cylinder. J is the ordinary slide-valve in the steam-chest A, operated in the usual manner, from the engine-shaft.

By'this construction of the engine there is secured from a given amount ot' steam four times the quantum of power, and, consequently, four times the quantum of motion of the ordinary engine, and the driving-pl'illey for any machine needs to be only one-fourth ofthe usual size to secure any given motion.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is-

The combination, with four pistons working within a single cylinder and having separate and independent pistou-rods projecting from opposite ends of the cylinder, of the four cross-heads connected two and two, as described, and then by strap-joints and connections with two separate wrists, substantially as and for the purposes herein set forth.

In testimony that I claim the foregoing asY my own I affix my signature in presence of two witnesses.

SAMUEL B.v FRANK.

Witnesses:

WM. H. LETGHER, J. R. LETGHER. 

